Rinse joints out - Paved courtyard driveway

Hello. We have a larger slope in front of the house. Over almost 7 meters it is quite flat and over the last 3 meters a bit steeper to reach the street. The slope is about 30cm per meter. The stone used is a 40x20 stone. I have already flushed and swept the joints several times, but unfortunately no chance with normal sieved sand.

What do you recommend, also in terms of your experience? We do not want dark mortar joints and ideally I only want to stabilize the front area. The color should approximately match the rest of the joints. Liquid joint stabilizer never seems to be drivable. Pure sand in 20kg packages with slight adhesive components or similar does not really seem to be durable, does it?

Basically, quartz sand is usually used. However, with larger joint widths, it also gets washed out. Hence the joint stabilizer. You don't drive on the joints, but on the stone. Therefore, it should at least be significantly better than now. I myself have quite wide joints and also a steep driveway. I use very fine decorative gravel (however, black). With heavy rain, some of it always gets washed away. That's just how it is.

You basically do not use normal sand at all. Instead, joint sand or stone sand (quartz sand) is used, which hardens relatively quickly and then nothing happens anymore.