The OP said he wanted the "best" way. IME, a string based RCM (Keith Monks, Loricraft or similar) used with effective cleaning solutions, including very pure water for final rinses, provides the best results. This method is expensive and time consuming, but the results are audibly superior to wand-based RCMs (VPI, Nitty Gritty) or ultrasonic RCMs.
I've tried steaming, using machines and regimens recommended by steaming proponents on this forum and elsewhere. The results were unacceptable. There are a couple of reasons for this:
First, steam does not dissolve everything. At temperatures and pressures safe for vinyl, steam is far from a universal solvent.
Second, regardless of what cleaning vapors or fluids one uses, allowing a grunge-rich solution to evaporate necessarily causes the grunge to deposit back out of solution. The grunge ends up right back where it came from... at the bottom of the record groove.
I've tried steaming, using machines and regimens recommended by steaming proponents on this forum and elsewhere. The results were unacceptable. There are a couple of reasons for this:
First, steam does not dissolve everything. At temperatures and pressures safe for vinyl, steam is far from a universal solvent.
Second, regardless of what cleaning vapors or fluids one uses, allowing a grunge-rich solution to evaporate necessarily causes the grunge to deposit back out of solution. The grunge ends up right back where it came from... at the bottom of the record groove.