re-racking is a con merchants way of getting the plane online again and very rarely actually fixes anything apart from allows the engineer to sign off the fault and usually means you re-start the deffered defect sheet the next flight or the next. The potential damage which can be done usually far out ways the benefit. And if its being done day in day out just to get the thing working it will lead to damage.
Replacing I have no problem with but re-racking is a easy sign off when you don't know or can't be arsed fixing it properly. Also the avionics might not actually have the moisture where the heater air can get to it. And the working temp of most avionics is way in excess of the heater air so the kit will dry out faster with use than with just cabin heat. If you re-rack once and the problem occurs again the next day its the seals on your connectors you need looking at not a constant re-rack.
MJ