I shoot Shockwaves also, they are tight going down. I feel this is why I get such great accuracy from my setup.
I run a "spit patch" with a little bit of T/C #13 on the patch after each shot.
I have also used Militec-1 on the inside of the barrel and on my breech plug. Militec is a dry lube that adheres to the metal. This helps with cleaning, making the gun a breeze to clean. It also helps IMO with loading the tight fitting sabot of the shockwave.
Another option is to go with the Hornday SST. It is the same bullet as the shockwave with the exception of the yellow tip and the sabot. The Hornday has a smaller sabot. This is better on some guns not so good on others. If the Shockwave is tight the SST might be a bit looser. Some Wal-Marts carry them as does Dick's. They are also a bit cheaper.
P.S. Militec-1 is here.....
http://www.militec-1.com/
If you decide to order some, follow their directions on "curing" your gun. Or pm me.