GPK files

GPK files are littering my hard drive. The time I spend getting rid of those files and making sure that my clients do not inadvertently receive those files is a lot more than the amount of time it takes for wave lab to generate overviews. I would like the option to not have these files generated at all, or at least to be able to choose a folder for them all to be saved to that I can dispose of conveniently. Thank you.