Repointing old patio

[B91]

1950s patio, 240 2' x 2' slabs in alternating colours. Just jetwashed it and joints are breaking up but otherwise still looks good. I will have to rake out the loose stuff but what's the best way to fill the joints again? Sand on its own is no good as rain can blow it out and sealing it is quite expensive. Repointing with a wet mix is a big and costly job too, but I was wondering whether just brushing a fine sand/cement mix into the joints during dry weather might be ok and then wetting it with a fine spray.

Any thoughts?

 

[Thermo]

do it properly with a damp mix. dry brushed will do exactly the same thing