What is best way to clean after using stain?

Just flush through with water. Make sure to pressure through hose a couple of times.

If still using daily, just submerge in water, that keeps the whole device as if it were wrapped up, no air, no drying of oil based stains, just empty canister and fill it with water, pump up a few times and spray for a second to fill hose w/ water and place the nozzle end in water, or you can just remove the hose and completely submerge it in water. I do that with all brushes, rollers, etc, that I'm using for oil based finishes, stains paints. The next day, just shake off the water and it's just like you never took a break! Make sure it is completely submerged or the stain will dry in those areas causing clogs, or half dry rollers

Take this apart and use the recommended cleaner for what you used. I used paint thinner and mine cleaned up very nice. You must take it apart completely and clean all of your parts and you cannot leave it sitting when your done. This is an item if you take care of it then it will take care of you for many uses.

I used Mineral spirits and water with mine. No problem