A very good point by the last poster............I've been a Professional Golfer, Professional Driver, Teaching Professional ( Lecturer ) Professional Cleaner only because I've been paid for providing services in these areas.
In all of these I came across people with considerably more knowledge than me, but I had the TITLE and I got PAID so they always assumed I knew more than them.
Some will do BASIC work with BASIC machines and chemicals and build successful businesses while others ( particularly nowadays ) get sidetracked by the CLAIMS and promotions of NEW products which really do the same job.
As always...........you have to figure it out from researching what others do, how profitable one product / method is against the others and then find out if it would work for YOU. Unfortunately it takes time and experimentation to find this out and can be expensive if you get it wrong.