dont look like anything scary to me,though pics could be better.same as others id rule out pm and whatnot.you sprayed them so even plain/clean water has dissolved solids,dust particals and other stuffs than when dried can leave a lil residue.
but you were right to panic...right to seek many opinions...and right not to take the first bit of advice given,,and right not to go jumping in head first to do a panic flush.
could put a yellow sticky trap up,it could tell you if theres something flying around you dont want.
good luck n keep er lit.