When the cat enters the box, approach quietly and sit on the floor near by, not like you are interested in the cat. Let the cat start peeing (if you are face-to-face with the cat, move around to the business end) and just reach over and stick that bottle under the stream. Try not to touch the fur or bump the cat in any way. If the cat stops peeing, just freeze in place with attention focused elsewhere and it might start up again. That’s what just happened with my little old lady. I don’t think it even had anything to do with me, she was just getting it going good.

If it’s going well, let the cat fill the bottle. Too much is better then not enough.

If the cat is easy to spook, another way might be to sit on the floor by the box with a book or your phone, so when the cat enters the room you are already in place.

It’s definitely worth trying, before purchasing the special litter and all that goes with that. Good luck!