Pressure washing

While we were in London last week, our gardener got the old pressure washer working again and experimented on a corner of the patio - what a difference!  I've been nagging MrHCB about it for a couple of years as the patio gets very slippery when wet.  He is always more concerned that the pressure will blast out the pointing between the stones.  He must have had a bad experience once upon a time.  But so far so good - it's not slippery, the pointing is still in place, and it is SO clean!!