It's possible to make or buy solutions here.. But most people do not need to.
but, if you need, you could also consider something like :-
http://www.eheimna.com/products/detail/Quick-Vac-pro
or
http://www.amazon.com/Pennplax-Aquarium-Air-Vac-Gravel-Cleaner/dp/B0002APYBI
too much visible detritus could be a result of overfeeding, or insufficient filtration (Or maybe water flow)
Just to add to Doug's suggestions, I've also seen an off the shelf "gravel vac" system that looked like a HOB filter, with a suction hose for vacuuming.
Like said, though, you want to merge your gravel vac with your (more important) weekly water change.