Did you mean $9.95, not sure if the a should have been there or if it was
a one.  Actually, they well sort of work.  A friend has one, and all it is
is 6 volts from 4 aa batteries.  The tip has a small gap in it, so when
you place it on the connection, this completes the circuit and shorts out
the batteries.  If you get it wrong though, you could appli 6 voltx across
two ic pins or a transister and blow it.  I haven't actually used one, but
for small things it might work.
73s
Butch Bussen
wa0vjr