Although a circulating air drying device is helpful (not exceeding 60C!),
you can try and drain your slides in a vertical position, particularly the
plus charge slides (if you are using them).  You probably already drain a
corner of slide after section pickup onto absorbant toweling.  Plus charge
slides sometimes permit a water bead under a paraffin  section, a tiny bleb
that when noticed, can be released with a sharp needle, or blade, then
drained in vertical position on one of the polypropylene slide trays or
vertical metal slide holder.  After that drying was superior even in a
regular oven. 

Just a suggested thought -


Gayle Callis
MT,HT,HTL(ASCP)
Histopathology Supervisor
Veterinary Molecular Biology
Montana State University - Bozeman
Bozeman MT 59717-3610