The only substance I would have any faith in for below-grade sealing is Hydraulic Cement. It will not be anything you can inject into narrow spaces, unless there's some new version. It's tricky to work with, since it can begin to set before you have it all applied.
http://www.ugl.com/drylokMasonry/patching/fastPlug.php
"One common application for special hydraulic cement blends is repairing cracks and leaks. Certain types of cement contain an ingredient which causes the cement to expand as it dries, filling in leaks and holes in concrete or other structural materials. There is often a need for this type of repair work because of the fact that ordinary Portland cement shrinks slightly as it dries. Places like basements in areas with wet climates are especially prone to leaks because of this. These special blends can be hard for novices to work with, though, because once mixed, the material only remains workable for 10 to 15 minutes."