Annoying dust sticking to sealant joints on caravan

I'm sure I'm not the first to whinge about this, but every time I tow the caravan on unsealed roads/tracks, fine dust (usually red) sticks to the silicone (or other substance?) based sealants used as waterproofing over every external joint, around the doors and windows on the caravan. While much of it can be removed with a high pressure washer blast, some of it stubbornly resists removal. It is unsightly, and requires a scrubbing brush, appropriate detergent mix and considerable 'elbow grease' at the end of each journey to remove, or at least reduce, the effect.

I have tried various commonly available sealants as an 'overcoat' on the original seals in an effort to prevent this occurring, but without significant success.

Are members aware of any tried and true product, or a paint that will stick to silicone, that they have used effectively to prevent this chore?

Maybe it's just an unavoidable fact of life travelling with a caravan around Oz...