Most toy haulers should come with an outside hose to wash down your toys before loading them. Mud will not be fun to deal with inside the camper, it will make its way onto everything (of course you will get some on your clothes and spread it around). Getting dirt out is just a matter of sweeping, or being lazy like me and using a leaf blower to blast everything out the back ramp. Unless you buy a huge toy hauler, your living arrangements usually suffer a little bit, such as counter space, furniture, and storage. You can bring extra folding tables to help out with counter/table space. Having a couch is nice, but you can cuddle up on a bed and watch tv or movies if you not covered in that mud. Bring a little portable grill to help with small stove top; steaks on the grill, beans on the stove.
I ended up selling my older toy hauler because i got so frustrated since there was hardly any storage area, constantly tripping on everything and having to rearrange everything every time we loaded, camped, and unloaded. Always having to move luggage, camping equipment, fold/unfold couches got old. I know this doesn't answer everything, but i hop it helps.