Although Steve will better answer this question, I cannot imagine degassing for 30 mins for one carboy? The wine in the carboy isn't supposed to come to a rolling boil.
Kit wines seem to be the most challenging to degass, personally, I've never had to rack more than once with Juice buckets and the wine made with fresh grapes is fine after one racking.
Dralarms - I couldn't agree more.
TonyT, I'm not familiar with what you have or how you are degassing with it, but I can attest that racking my wine once degassed it, with the exception of wine kits that I had to rack twice.
Sour_grapes - You are correct, the optimum temp to degass is between 70°-75°.
SouthernChemist - I'm fairly certain that TimV wrote the article that you read about putting a bottling brush in the carboy to accelerate the degassing process many years ago, but I for one would not want a bottling brush immersed into my wine for any length of time, even if it were uber cleaned and sanitized, it just seems like the perfect vessel to carry spoilage organisms, we go through so much to keep everything sanitary, that seems like taking a few steps backwards, but that is just my opinion.