Spray block paving, roll tarmac, brush PIC.
Rolling block paving you'll find sand that you've just brushed in lifts out and collects on the roller. Common sense.
Goizper sprayers aren't for sealants. Gloria's are good and worth the money. I use one from Adseal that holds 12 liters (forget the name of it) looks like a red fire extinguisher. Was about 115 after VAT. They do a cheaper one too, all plastic, holds less but you have to keep cleaning the thread otherwise it seals and you'll end up breaking it to open.