The "dishwasher" problem really got my attention as we thought our home
was completely "ferret-proofed" already until we adopted "Effe".  She got
past the wire mesh that had kept everyone else from running behind the
stove, so that had to be re-done in a "snugger" fit.  The same protection
was being used on the dishwasher, but since it is an "island" type that
must be rolled to the sink for use, we just could not get all the gaps
closed around the wheels.  You did not mention if your dishwasher is this
"free-standing" type, but if so, be forwarned that we tried assorted
baricades (she got past 'em) & plugs in the wheel holes (she pulled 'em
out) & nothing worked.
 
I'm lucky to have a "handy" man, who turned the dishwasher upside down &
snugly fitted heavy corrugated paper (cardboard) all across the very
front edge behind the wheels & extending further back.  The whole thing
is securely taped flush with the edges underneath.  Now, when the fuzzy
snuck under the front by the wheel holes, she could not go any further!
Since she can not crawl up inside or get to the insulation, it isn't
dangerous now.
 
I wish I could say she has given up, but she still occasionally "digs" at
the tape underneath trying to get it loose.  She may eventually succeed &
we'll have to re-do the whole thing, but it's been working for several
months now.  Good luck!
 
Lisa
[Posted in FML issue 4806]