I don't know how i feel about it to be fair. Although it is nice to see that an owner is doing everything they can to try and improve the quality of life for their rabbit which is refreshing to see.
To be fair, I have put Lucy through hell this week by syringe feeding her, administering approx 5 different drugs, applying eye drops etc and she hated every minute but it was necessary. If we all thought, I can't do that, it would upset my rabbit then we wouldn't administer drugs and nurse them when ill because they got stressed.
My meaning, if it is in the best interest of the rabbit then I don't see a massive problem but obviously it is not ideal for every rabbit. By the sounds of it the owner thought they would try it, thinking the rabbit would hate it but because it didn't seem too bothered and it appeared to help they continued.
Being in the veterinary field, I would need to look in to it further to form a better understanding and opinion to be honest.