Yes, you should be able to use your flask. I would use the smaller wire though as a cathode. Get the electodes as far apart as you can. If you cant get the voltage up to 10, raise your electrodes higher.
Like you,I use a Erlenmeyer flask also. I use the bullion bar and Kep's #12 wire as the cathode - NO PROBLEM. MY spacing is very close to 1.25" The cathode typically will be a half inch of so in the solution in order to get
10 volts across the cell. When you start the process, just adjust your cathode to get 10v on the readout. I just produced 40ppm and 320 using this exact method.
A smaller wire will allow more of the cathode to be in solution. Some folks use copper wire for the CATHODE. I have made copper cathodes of various sizes but have not tried it myself yet.
I USE A HOTPLATE/STIRRER to keep the solution in motion. My results have been reproducible and GREAT!