I always watched my airspeed impecaby, not necesarilly increasing it though.
I flew in a glider once, with an experienced pilot, I cocked up the approach, he took over, and put the aircraft into a sideslip, I looked at the ASI, and to my horror watched it reduce off the scale, along with the pitch up manouver... When I asked him about it, he just said, "oh, you should never look at the ASI in a slip"
That brings me to a question.... I tried it in a Citabria, not alot happened... That is stalling in a side slip...Is a sideslip a stable manouver???
ie: I would have thought that having crossed controls would be pro-spin. But it doesn't seem so...
Bag of worms????? I dunno.