Yes, I know what you mean re. removing their biscuits. I feel the same, but sometimes it can’t be helped. I would try some of the other deterrants at the same time, i.e. filling in bolt holes, etc. to help encouraging them to move on more quickly. When I have had them in the past, I poured water down the hole first to make sure no rat was in there before filling it in – wouldn’t want to bury a rat! I was quite pleased that a rat never came leaping out of the hole, though – which might be a risk! Although they could probably dig their way back out.
Good luck. I hope they move soon.