You do not need to pound in the plug
A light tap is all that is needed, an aggressive impact will drive the plug in so far it will be difficult to remove. The plug is only used until the proper repair can be completed. The plug is used to slow/stop down the flow of water and allow the area to be excavated for the real repair work. The plug will naturally expand to hold itself in.
Corporations are typically pulled out by excavation contractors digging in the streets. The corp will typically shear at the closest thread to the saddle or direct tap. You will need an easy out to remove the remaining threaded section if you plan to replace the corporation with a new corp. Otherwise, a repair band will go over the hole, set the repair band on the pipe next to the wooden plug assemble the clamp so it is ready to tighten, work the plug loose and slide the band over the hole and tighten. This can be done under pressure but not the driest of jobs.
Plugs are available from USABluebook, Pollard Water, or your local Water works distributor.
The standard plugs work well in corps, to plug pinholes you will need to get the small ones or just whittle the standard ones to size. Note on the pinholes, inserting the plug will enlarge the typical pinhole as it is driven in, curling the thin area until there is enough meat in the pipe to hold the plug in place.
Bimr, call me a hick but we used a plug last month just as described above corporation example.
Hydrae