An old trick of “last resort” is to actually play a record while wet.
For reasons not fully understood (by me), doing this “quiets” the record substantially (removes the noise caused by scratches) seemingly without reducing fidelity. I recommend using only water without any chemical, as the chemical may cause harm to your stylus and cartridge. This trick is best used when trying to extract the best possible sound quality from an old, mostly worn out record when you are recording it. Expect your stylus to be dirty and in need of cleaning upon completion, which should be done immediately before it dries.
Really dirty old records will require several cleanings and playings before they yield their best sound reproduction.
If you are really serious about playing many old and dirty records you should consider getting a very sturdy stylus/cartridge such as the Stanton DJ series. These can stand up to the abuse of older, damaged records much better than the more expensive and sensitive stylus’.
I do not have an opinion regarding products that “treat” the surface of a record (such as “Last”), nor with cleaning products ( like Revirginizer) that are like a “face peel” for records because I have never used them myself, probably because I have not felt the need for them.