i suppose it...
is possible, but how close is the enclosure to the sink you suspect (s)he went down? it's unlikely that your snake would have travelled to an area that didn't provide many places for it to seek shelter(such as a bathroom or kitchen). they often go up when they escape, so...under sofa cushions, behind curtains, even tucked away behind a few volumes in a book shelf. i often handle my snakes in the bathroom because...i don't know. when i need to soak them or remove unshed skin i tend to do it in the bathroom because the light is best in there. my snow almost got under the toilet seat, into the bowl and my hatchling tried to cliff dive off my hand into my sink, but both of these occasions were ones when i actually took them into the bath. i don't think they would be able to find a way up and into the sink or toilet bowl...or tub drain, but you never know.
good luck finding your snakey-woo! :crazy02: