I have something similar, got it at the dollar store. It's used to bath big dogs it has a compartment for soap you attach a hose and flip a switch for water only or soap mixed with water. Cut bath time in 1/2 and saved my arms. I give 3 biggies and 2 mini a bath in about 3 hours.
I use the EZ ALL foamer. LOVE IT! I have 5 Shires and 4 minis. Cuts bathing time in 1/2. I also like their cleaner as it is plant based. A little pricey but works greats. I think it was well worth the expense. I ordered mine online. Just go to search: EZ ALL They have there own web page.