Hi 'Simonr' - big dogs and small dogs - yes it works - but as 'grevillea47' said - unless there is supervision and training - then it could turn to tears !
Instead of getting dogs straight from the pound - why not look at rescue groups ? These groups foster dogs for a time in a home situation and put the dogs up for adoption - when the dogs are ready.
You will get a lot more useful information regarding temperament and behaviour of the dogs than going through a pound.
A link for you:
PetRescue - Inspired by unconditional love - PetRescue
Good Luck !