I use a variety of materials to fill hull bubbles; Bondo catalyzed body putty, Bondo Red glazing putty, CA (either straight or mixed with resin dust), and/or styrene plugs.
By Texas (BB-1), I know that it is the Iron Shipwright product. They often have problems with bubbles on the bottom of the hull. Open any pin bubbles you may see with the tip of an Xacto and overfill with putty (Squadron white is like Bondo Red -- both are solvent based putties, but Bondo is cheaper). When dry, wet sand the putty -- but don't be too aggressive so as to not open more holes. If the bubbles are just pin points touch a pin with CA to the hole and sand right away. For bigger holes, CA a piece of styrene rod or stock into the hole and fill with putty -- the styrene acts like an armature to hold it firm.
Also, remember that Iron Shipwright has a customer satisfaction policy. If your hull is too damaged that you cannot work it, contact Ted Paris at the address listed (or google Iron Shipwright) and tell him what is wrong. Ted will make the problem right.