What is the best way to clean Vinyl?

Just beware that "wall wart" powered Ultrasonic machines like the Humminguru and all of the even cheaper knockoffs you see on Amazon do NOT provide in any way, the same level of small bubble formation and cavitation and cleaning that "real powered" ultrasonics do. Try one if you want, but if your results are "so-so" don’t blame it on ultrasonic cleaning not working, but rather on the lackluster properties of said machine. It’s like if you want to take photographs. You can do "ok" with a cheap cellphone or you can buy a DSLR and get much better results.

Yeah, "real powered" ultrasonics cost more (a lot more), but then they give the benefit of the actual cleaning method as DESIGNED. I use a homemade motorized vacuum system myself (uses the $30 Vinyl Vac as the basis of it, and cost around $300 all in) and feel the results are "good enough" for me, as vinyl only accounts for about 20% of my listening.

The Humminguru might be "ok" for brand new albums, but I wouldn't expect it to do much on used albums you find at yard sales, thrift stores, or some local record stores that sell used items.  For those you need something more, maybe a cheap Spin Clean to augment it. 

Finally, if you are new to the hobby of vinyl, understand that cleaning gets rid of gunk and junk in the grooves for less snaps, crackles, and pops, but it can't work miracles on records that are actually scratched.