EDM speed

I need a 1/8" square hole about 1/2" deep in steel to hold a cutting
bit. The bit will be held in with a set screw so dimensions are not
overly critical. Would the simple "light bulb" EDM be capable of
this and if so how many minutes or hours would it take? I can drill
a 1/8 through hole first and can probably find a way to circulate the
fluid through it.

Or should I give up now and change the design to a round hole?

Thanks

John