Simple Green & Wolman Deck Cleaners

I've been getting some bids to clean & seal my new deck (approx. 4 mths old) and one uses a "green cleaning agent" (I assume is Simple Green) and the others use Wolman. Are either very good cleaning solutions? When I asked about doing a 2 step process of applying a cleaning agent followed by a brightner I was told each contained both, which I find suspicous after researching on this site and finding the resulting pH of both are total opposites. Should I insist on using both a cleaning agent then a brightner or will either of these products do a good job?