Do I need a record cleaning machine

It is imperative that new albums get a good wet cleaning and vacuum dry before a stylus ever meets the grooves. I recommend a good three step process like Audio Intelligent or Walker products. Those enzymatic agents work miracles.

nearly 20 years ago i had a cleaning machine, but always found that cleaning manually was at least as effective, and sometimes more effective. if you try to salvage old records which are really dirty then i'd say one is necc. otherwise its a coin toss. anyone who has done it manually, usually developes 'a manual system' that works, and isn't terribly painful to do.

I agree with Xiekitchen.
In my opinion it's a must, and I prefer to use the Audio Intelligent Vinyl Solutions Enzymatic Formula solution.

can anyone suggest a manual system for cleaning lp's?

Steaming is a great way to lift the dirt but then you need to wash it away.