you don't really need any chemical cleaner; in most cases, simply power washing will return the paving to it's best, but, if you have bad staining, a degreaser such as Jizer or plain wash-up liquid will do as good as anything. Acetone is useless, unless you've spilled paint or nail varnish!

Many of the so-called 'paving cleaners' contain weak hydrochloric acid plus a detergent and some perfume. The HCl works by eating away at concrete pavings but has no effect on clays. The detergent is ok and the scent/perfume is a waste of time and money. Be VERY, VERY careful if using these, as they can irreversibly alter the colouring of concrete pavings by reacting the HCl with the Iron Oxide of the concrete dyes. Test on a hidden corner first.

Once the drive is clean and has be re-sanded to fill the joints, have a look at Resiblock 22 as a sealant. It ain't cheap, but it's certainly one of the best paving sealants available. More info on the Sealants page.

Dexter

1 - it's been developed especially for use on block pavements rather than a 'jack-of-all-trades' product like Water Seal.

2 - it's a SPPU rather than an acrylic

3 - it binds the jointing sand as well as seals the surface.

4 - it has been extensively tested in the most aggressive of conditions, including airport runways.

5 - it *should* have a lifespan greater than an acrylic, possibly twice as long or more.

6 - it comes in a variety of finishes including gloss, satin or matt, to use paint terminology.

7 - it's used by the trade for the trade, whereas Water Seal et al is more of a DIY solution.

Have a look at the Resiblock website