So, it's clear to me that I am going to have to start using the cardboard/paper plate/plastic under the feeding method. Rats seem to collect far more substrate than mice did, but anyways...

Right now, there is visible substrate in Sushi's mouth. The post-meal yawn revealed a patch or two of what must be coco husk. Should I rinse it out of there? And if so, do I just use the q-tip stick method of opening his mouth, then flush with clean water in a syringe or something? Seems like the logical way, but I figure it's best to ask first.

Thanks in advance!