Fingers are fairly easy to remove the foils in a copper II chloride leach. a smaller 1 gallon plastic bucket that will fit in a three gallon bucket works well, drilling many holes in the 1 gallons buckets bottom to act as a strainer, a few holes at one of the bottom edges corner help to drain the last bit.
The foils sit in the 1 gal. bucket and it is lowered into the three gallon bucket full of the copper II chloride leach, this way it can easily checked on, and be stirred by lifting the inner bucket and lowering it (normally fairly slowly so as not to push solution out of the larger bucket), the small bucket act as a strainer holding the pieces of fiberglass, and lets the small foils fall through the strainer holes to the bottom of the larger bucket making collecting the foils easier.
The copper II chloride leach will work in cooler weather but its action does slow down, it cold outdoors it may seem to stop reacting. Here you may choose to have a little heat, you really do not need too much heat, and there are several ways you can provide some heat, a box or large cabinet with a door and a light bulb inside where you can sit your bucket inside. this could be made or use something you may already have like an old refrigerator...
Blanket bucket heaters work well these are flexible blankets that wrap around the bucket, you can get these with thermostat control, another option I have used (it works but is not the best is a fish tank heater), A crock pot on low heat (but they are almost too hot even on low), the process is slow even with warming, so a coffee pot on a hot plate would not be my choice, but you could use it.
You do not want to get the solution hot, just warm, about normal room temperature, or as hot as a warm sunny day is just fine.
