i used to have this happen as well.  i bought the george merrill system.  the common denominator is the fact that the water either drys on the record leaving crud and a static charge, or if you use a blow dryer or even a cloth, it imparts a static charge.  i found an old nitty gritty base model on a-gon for about $125, so i now use the merrill for cleaning and then run it around the vacuum a few revolutions per side for a far quieter record.  this works on old or new.

Yep, static electricity. Especially since the noise lessens over time, as the static electricity naturally dissipates. Either clean and set aside for a period of time, get a ZeroStat or change whatever it is about your surroundings or the Spin Clean that's contributing to the creation of static electricity.