It also appears in his laundry room in "Dumped" as a clothing wringer, however this is different from the one kept in his bathroom.
"Stuck in the Wringer"
The wringer plays a very important role in the episode "Stuck in the Wringer." SpongeBob slips on Patrick's Rubber duck and gets stuck in it, and this causes him to have a mishap-filled day. His problem only becomes much worse when Patrick uses his Forever Glue on it which causes SpongeBob to be even more stuck, this leads to a chain of misfortune for SpongeBob, resulting in SpongeBob angrily lashing out at Patrick for ruining his life, Patrick runs off crying as a result, ending his friendship with SpongeBob in the progress.
Near the end of the episode, SpongeBob and Patrick cry tears as a result of their friendship declining, which melts the glue and frees SpongeBob. Once he is freed from the wringer, SpongeBob throws it up into the air to give Patrick a hug in celebration of their reconcilation, however, it lands and traps both of them in it, though this doesn't affect the pair since they are at least glad to be stuck with each other.