The amount of baths your Papillon needs depends on your life style.
Some pet dogs are very seldom bathed, but if they are brushed at a regular time, they can stay very clean.
A sink, tub with a shower attachment and a non slip surface to stand on , is all you need.
Avoid getting water in the ear canal.
(I do blow dry the their hair after bathing , brush them, and let them wear a sweater for a while, to keep them from getting chilled.)