hey captain

From my experience with carbon filtering the more you filter it the better off it is, although this does take more time etc etc, but upon searching various vodka companies, the most expensive vodkas are triple distilled and up to four times carbon filtering.
I usually only double distill and single filter as the taste turns out very good with one filtering.

I like to put my charcoal in a stainless container and put it in the oven at 450 degs mixing continually 1-2x per hour for about 3- 4 hrs until no more alcohol smell is given off, then I pre wet again and get it ready for the next batch.

For me when the flow rate drops and very little spirit is coming out of the filter is usually when I clean and reactivate the carbon.

Somking T you are giving bad avise. The secret is to let the spirits flow through the carbon slowly, the more the spirits is in contact with the carbon the better the spirits. Since the carbon is pre-wetted is does not benefit you to double filter. However, if you double or triple distill than you will get a better spirits. Most people will not double or triple distill. The spirits are not carbon filtered before double or triple distilling. As to activate your carbon I always boil the carbon two or three times between distilling and the day before filtering. To re-activate you need to either put in the oven or on a gas grill outdoors for 2-3 hours to clean the waste product out of the carbon. The heat allows the impurities to form like a glass product that will fall out of the micro and macro pores of the carbon. Remember the fumes from the carbon while in the oven are very flammable, that is why I use a gas grill outside to re-activate my carbon.

C .....freebrew

Bad advice? Most people do not double distill , well maybe they should start double distilling as you get a way cleaner product, like I said before the most expensive vodkas in the world are usually double or triple distilled, and double or triple filtered, Check out there websites.
if you use Gert Strands method of carbon filtering, pre boiling your charcoal 3-4X's and then let it sit for 24 hours in the water, fill up your filter and do not allow any air in the charcoal you will have a great product, by repeating those steps and filtering it again you will have an even better product but hey bad advice right???