Your bird is a quick learner - that is a good thing. Now you just need to control the contingencies for his behavior.
First a comparison to the most often heard problem in house training a dog: "we take him outside for a long time but he wont go, as soon as we get in he pees on the floor." Of course, the dog has learned that peeing is the end of all the fun - he goes outside, sniffs, explores, plays, then if/when he goes in a good spot he is brought inside and the owner goes to work. Instead the dog should be taken out of their crate in the morning, brought outside on leash strait to a tree or other good spot, given a moment or two to go, and if they don't they should be brought swiftly strait back into the crate for a minute. This can repeat over and over (and over and over) until the dog goes outside THEN he can hang out outside, play, sniff, explore, roll in dirt, etc. All the fun comes AFTER he does the desired behavior - don't make the desired behavior the end of the fun. That idea right there solves 99% of all 'severe' potty training problem within a couple of days. And a similar problem is at the core of many pet behavioral 'problems'. It's not a problem for the pet, they have learned the contingencies quite well - rather it's a problem for the owner as they must realizes they are in fact rewarding bad behavior and punishing good; until that changes the pets behavior wont change.
My suggestion is to build a pattern and procedure for cage re-entry. For example whenever I need to leave I rinse and refill Auggie's water dish right before I leave. I refill the water, he goes in the cage, then he gets a special treat that he ONLY gets for going in his cage (dried blueberries in Auggie's case). Now when I refill his water he is running to get into his cage and onto the perch where I hand the blueberry through the cage - if I'm too slow with delivering the blueberry he'll pace back and forth on that perch until he gets it.
Your senegal needs to learn that he'll get more good stuff for going in the cage when asked than he'll loose by going in. The important elements are a discriminative stimulus: water dish changing for Auggie, or a command such as 'go to your house', etc - it's just a bit of historical accident that the water dish changing is a more salient signal to Auggie than is the command, though he responds to the command fairly well now too. Next is the behavior of going to a particular spot in the cage to collect a reinforcer - I'll get to how to train this behavior in a moment. Last is the reinforcer/reward - this needs to be a really good reward, and ideally will be specific for going back in his cage; this could be his favorite food for example, but with it he should get plenty of praise and attention through the cage for a bit.
Now, certainly it's easy enough to reward a behavior once it happens, but how do you GET him to go in the cage the first time so it can be rewarded? It is possible to just grab him and PUT him in there, but this is not preferable for many reasons, it is available as a last resort or as a stepping stone to the better method. The better method is to lure him: find that treat that really motivates him and keep it just out of reach leading him into the cage, lead him to a particular spot then give him the treat. Do this many times and transition to pulling it away at the last moment and handing it to him THROUGH the cage (he's inside, you're out) while you close the cage door. For training he should go in the cage, get the reward, then be let out right away again. He needs to learn that when he goes in the cage (when asked) he gets something good and looses nothing.
Right now when he goes in the cage he gets nothing (or very little) and looses a lot. There should be no surprise that he will not do this willingly.
No living being does anything without reason - expecting our pets to do what we want is crazy, they will do what THEY want. It is our job to control their environment such that our goals/desires converge: You want him to go in the cage on command, make it so that HE wants to go in the cage on command.
I do defer to you and many of the other members because I am a newbie when it comes to birds. But sometimes I remember a tidbit that I read or something that I have learned from my experience so far that no one else has posted so I throw it out there incase it will help. I'll try to be a little less sensative in the future.
