Snap, crackle, pop

Yeah, considering where you live, you don't have a static problem. So my guess is the rice krispies come more from worn vinyl than dirt.

Glad to help with the "white ring". It is a telltale indicator that the records were not taken care of, either on the tables they were played on and how they were stored.

Just keep hunting down the best copies of a particular title you can and enjoy the music Brother!

The better the cartridge and arm, the fewer snaps, crackles, etc.

IME, an enzyme-based cleaning solution is the best cure for most snaps, crackles and pops. I have a $2K Loricraft RCM (one of the best) but cleaning with just surfactants ("soap") and rinsing does not remove everything.

The grunge in LP grooves provides a breeding ground for microbial growths. Many of these (or their carcasses) are not easily dissolved by surfactant action alone.

Enzymes, however, are chemically designed to break down organic matter. They will attack and help dissolve stuff that soap and water will not.

Having compared 4 brands, my best results come from AIVS solutions, with their Enzymatic being the most effective for removing snaps/crackles/pops.

BTW, having dissolved all the gunk in the grooves you still need to remove it. A Spin Clean, while economical, will not remove all the grunge-laden liquid before evaporation begins. Allowing the grungy liquid to evaporate leaves the grunge behind, probably broken into smaller particles that may be even harder to remove.

A vacuum-based RCM is the only way to quickly remove grungy fluids before evaporation undoes the work you began with the cleaning steps. You needn't spend $2K, but if truly clean records are your goal, you need to do more than spin.

My experience and $.02...

Some preamps will emphasize ticks and pops as well!

Sometimes the loading on the phono cartridge can help too; a lot depends on what cartridge you have and the phono preamp.

You can get enzyme based cleaning solution at much lower price tag. Once audio comes onto play the price bumps-up 10x at least. It's simply an enzyme based surgical tools cleaner which retails anywhere from $50 to $100 per gallon(check amazon http://www.amazon.com/s/ref=nb_sb_noss?url=search-alias%3Daps&field-keywords=surgical+enzyme+cleaner).
1 gallon can clean about 2..3,000 vinyls depending on contamination and it works indeed best.
Ultrasonic cleaners usually consist of an ultrasonic bath.
To fit 12" record size one should retail at $3...500 range depending on width and electric slow-rpm motor or one with reductor. Also you'll need to put together some frame for the motor. Plywood is fastest and cheapest approach to build it.
With ultrasonic cleaner all you need is distilled water, but if vinyls are highly contaminated, I'd purchase one of those enzyme cleaners in smaller quantities if possible. A gallon would be sufficient for 5k vinyls if not more when using an ultrasonic machine.
Dryer is optional especially when using enzyme cleaner. Vinyls will normally dry out with no residue at all, but optionally i'd build one using blower motor and pipes from the hydroponic gardening equipment.
Purchasing separate ultrasonic transducers and SS bath may save you even more since you don't need heater that usually supplied with any ultrasonic bath