I am an erstwhile- (on second thought- still part time :-)  PA who quite
often still  embeds his own stuuff the next morning.  I agree with Jeanine-
if you are careful not to overfill the cassette leaving 1 mm at the top,
then there is usually no need to scrape the sides of the cassettes clean.
Don't scrape and soon the block clamp jaws  become encrusted with paraffin
and then blocks start to slip around and chunk because the clamp does not
get a clean bite. We use old very dull paring knives with wood handles- its
sort of like shucking clams. My thumbs ache just thinking about it.
With regard to trimming the block face around the tissue, I used to do this
for biopsies but now I have a pathologist who screams if I do this- she must
look at everything on the slide so she wants few- if I ribbon a vas or
something- I hear it.

Jeff Silverman
Southside Hospital
Bay Shore NY USA