Easier then bathing might be using a little drop of perfume or deodorant, that you rub in their fur, not too much cause it might be toxic if they lick it off, but enough to cover their own odour. And introduce them in a small box, leave them there for some time and then put them in a fresh cleaned cage (clean everything, hides, hammocks... whatever) This routine worked out fine for a friend of mine, who is quite experienced in breeding rats, other than me... Some rumble in the jungle might happen, but they should settle down after a while.
By the way, my two dumbo boys also know I am the most evil rat in town, when they get their two minutes of rage sometimes... a little call for discipline in the cage and the two are "best friends" again...![]()