what is the fastest free way to get at least 1 satoshi
There are no shortcuts, nor any free rides.

First off, you aren't going to be able to do anything with 1 satoshi.  You wouldn't be able to afford the mining fee to transfer it anywhere, which means that it has essentially been taken out of circulation.  As it stands, everything you can do with 1 satoshi you can currently do with 0 satoshi.  For amounts that small, you shouldn't bother.

Second, your time has value.  Regardless of your electricity costs, setting up a CPU/GPU to mine bitcoin will take time.  Furthermore, with so little hashing power, you aren't going to see a payout anytime soon...even while mining on a pool.  You are probably better off trying to use the faucet you mentioned.

As it stands, the least expensive (both time and money) and fastest way for you to obtain a usable amount of bitcoin is either to purchase some, or sell a product/service in exchange for some.

I know this is not what you are looking for, but I assure you that it is the truth.