You can do it with Autos no problem. I made my silver colloidal solution a few weeks back and my Big Bud X Norther Lights auto is showing her balls:
Plenty of guides out there. Here is how I make silver colloidal solution.
Two silver coins .999pure silver only. I am cheap and purchased small 3gram coins(8bucks for both on ebay); bigger coins would be better since you do NOT want the alligator clamps touching the liquid.
Clamp on the coins and submerge in water (again, don't let metal clamps touch water...just the silver coins)--I have a second set of clamps so that I can position the coins away from the sides. With such small coins, I would make no more than 16oz-24oz of solution at a time. This picture shows the coins in place...I would bend them/move them a bit more toward the center of the pitcher.
This silver colloidal generator is powered by the power-supply from an old laptop -- I purchased it from good will.
The above shows the approx DC output you are aiming for (DC9Volt 600ma-2amp)...some folks just us a 9volt battery -- I prefer the power-supply for stable/consistent output. Also, 9volts can cost as much as this used power-supply cost:
I use a small fish-tank air pump to mix the solution; this is probably not necessary. The above picture is the complete generator with the good-will power supply attached to alligator clips glued to the inside of the pitcher. The secondary alligator clips are soldered to lengths of silver solder to extend the coins where I want them. I have the coins in roughly the position you want them in (again, move them more toward center of pitcher than what you see in the photo) -- inch or two apart.
Fill with distilled water up to the top of the coins. Since the coins are small, I run this 24 hours. You will noticed some pitting as the silver is driven into solution...and some corrosion will float around as well. My solution turns a light amber color...I wouldn't worry much about the color -- If you run the above current through the silver in solution...it works.
Bottle up the silver colloidal solution and spray your plant 2-3 times a day. Do this just as you begin to see preflowers -- Start spraying 3+ish weeks into your grow. Monitor you plant carefully...back off the spray if you are stressing her out too much. When you see balls...stop spraying at let them fill up with pollen.
Store the colloidal silver in a dark place...have fun.