Klean Strip "Premium Sprayable Stripper".  Works well, but must be sprayed in a mist--will be much more effective and faster.  If you put on too much, it will slow the process.  And you MUST wear a respirator, not a P95 mask.  It's a very high VOC organic solvent.

Any pump you use will be finished when the job is finished.  I would agitate & rinse.  May not need a lot of pressure, but some would likely help.  I used this stuff to remove paint & urethane seals from floors in a former life.  If you use a pump sprayer, keep the pressure mild to medium.  Don't use it as you would for water based cleaning solutions.  When you buy it, there should be a small spray bottle to use as well.  Use that to treat the edges so that you are not broadcasting a large pattern as with the pump sprayer.