The quickest way to learn to speak Polish or any other language is through the total-immersion method as pursued by Berlitz and other schools using similar appoaches. It means 6-8 hours of exposure a day for a minimum of two weeks (two months is even better). There, at lunchtime you don't even get the salt unless you ask for it in Polish, and the question "Where's the nearest loo" will draw only a blank stare from teachers and management.
The downside: the cost and daily time budget which not everyone can afford.
The downside: the cost and daily time budget which not everyone can afford.