We have inherited a fake beach/terrace thinggee from the previous home owners. It's mid 90s and has 20 odd years of leaf litter in it esp from some canna lillies I just pulled out and palm debris (seeds etc) .

Weed have been growing in it more frequently. We'd like to rehab it, and reuse the shells, but need to some how get the, well, crap out of them. We'd rather reuse than replace, as landscaping supplies are expensive.

Any suggestions welcome. I don't mind doing a bit of grunt work.