Termite leaving sand on wall
Cleaning your walls won't help; you're only taking away the crud your termites output.

Filling in the holes won't make a difference to the original problem of termites eating away at your structure. This might make things look good, but stuff is rotting away deep inside, and no amount of lipstick can fix that.

Please call an exterminator. That's certainly more expensive than just covering up the damage, but if you want your home to stay structurally sound and livable, you'll need to repair whatever damage has already occurred.

EDIT: Your profile indicates you aren't in a wood-framed house, in which case my answer would probably not apply at all. You'll need to figure out what your termites are after (wood, other food), and remove that attractant. Calling an exterminator may still help.