Hi,
Sorry to have to disagree with you here but never ever use a wacker plate after an installation as all you will do is break the blocks.
A wacker plate is not used to help kiln dried sand penetrate deeper although this does help on installation.
When you install a drive the blocks are set aprox 8mm higher than finished level then the kiln dried sand is brushed over the whole area.
The wacker plate is then used to compact down the blocks to finish level.
I’m not trying to upset you just advice as I’ve been installing driveways for many years have a look at my web site.
PS: If one or two of the blocks are too high just use a rubber mallet or a bit of 4x2 and a club hammer to gently tap them down.
All the best
Mark
http://www.grimeforce.co.uk/befor-after.htm