most rental shops use an amonia based spray disinfectant (like febreze or microban). it will take care of the bacteria and fungi (smells), but it wont get the soil out and leaves a good amount of biological matter in there for things to grow in again.
i dont trust any washing method to not ruin the liners, i never even take my liners out. they just feel different any time i put them back in.
if im travelling on a plane with my boots out, i just put a bunch of dryer sheets in there.
fresh liners from intuiton only cost like $250, thats really the only way get rid of them smell. so you might as well try washing them in cold water.