Use a product called "Get Off My Garden". Comes in green granules and i've found it the best out of similiar products and is citronella crossed with something else. Beats the green jelly style granues (lasts longer) and if you keep reapplying it it they'll get the hint.. All the Better Pets and Gardens stores sell it but you can find it at some of the City Farmers et al too!

Its probably the best legal way to get rid of them

Tabasco and wasabi etc work well when dogs and cats are eating things they shouldnt be too!!