PTR
Striker
If you do it every year, it doesn't get too bad.Takes a few days and very messy doing it properly mind.
Week 1 - Spray with roundup. Leave 2 weeks
Week 4 - Pressure Wash
Week 5 - Brush in kiln-dried sand and spray with 2 coats of sealer
The weedkiller makes the amount of shit that comes out far less and easier to get out.
Doing the pressure wash on its own with no other jobs makes it less of a fuck on.
Need to be left for a week to dry out before putting in the sand for best results.