in my experience with aquasoil. it shouldnt be a problem even if you've taken them out of the tank for some time. remember what's it like when new?
dry and dusty as well!
so just put them in and fill with water. shouldnt be a problem at all. =)
however, remember to check water parameters after filling it up. water changes should be carried out as normal and no i don't think you'd have to wait 4 weeks before stocking fish. just dose a little bacteria cultures to get things started and start stocking 2-3 days later.