Bosher, dosher, osher and sacher
dasher ; washer ; splasher
"Glosser", "posher", "masher" and "closer" all rhyme with "washer".
No, do not expose your paintball gun to water.
If you mean end rhyme, 'fun' rhymes.
Smart gun
blowgun
The devils gun
big bum
caffiened nun
electron gun, favorite son, submachine gun, cinnamon bun
One word that rhymes with pun is "fun."
Gun