Crevice cleaning ideas?

Can anyone give advice on how to get the crevices clean in my seats? I have tried my home vacuum with a 'crevice' attachment. It does get some of the stuff on the side crevices.... but the stuff in the back seat does not vacuum out. I might try to tape up 1/2 the hole to make it even higher pressure, but I think it might need some physical manipulation to loosen it.



I bought this 'fan brush' and thought it would help... almost a complete fail... it got very little movement and doesn't seem to be loosening the stuck stuff. ...and the brush is actually quite a bit smaller; widest part of the bristles is about 1 inch wide.







I'm looking for ideas or suggestions. I don't want to go buy a new vacuum. I have more time than money... that's for sure. I'm leery to 'scratch' stuff out my leather seats.