If you want clean records, highly recommend Walker Enzyme. Tom Port recommended it to me, its all they use at Better Records, and it is clearly obviously easily superior to the Disc Doctor system I was using before. I don't use his expensive final rinse water, just my own filtered, and vacuum the final rinses off with my VPI, and still it is awesome.
Second hand vinyl surface damage.
Most analogue enthusiasts enjoy perusing and buying second hand vinyl. I was doing so this week, and picked out four LP`s that I wanted to add to my collection, but only after carefully inspecting their surfaces. Naturally a delicate item such as an LP undergoes `ageing`, a thirty plus year old desirable will not have escaped some surface damage. There are occasionally long and short deeper scratches, and more often clusters of light hairline scratches. If you want it you will have to put up with the result of said surface damage, so what do members consider damage enough to regretfully put the LP back on the shelf?