Yet another reason why fermentation buckets/bottling buckets with spigots are the bomb!
I just loosen and remove the airlock and put a plastic kiddie cup over the airlock hole in the lid.
(Why? Because when I do the next few steps, I 'm going to create a vacuum inside which might suck in the fluid within the airlock--whether it be vodka, starsan, boiled water, or whatever--I'm not crazy about it being added to my beer).
I remove the Ranco thermometer probe from the cheap pouch I've made on the side of the fermentation bucket. [I create it by folding paper towel multiple times so that it is the size of a 6 inch ruler and apply it over the probe on the side of the fermentation bucket. I then use clear packing tape to secure the folded paper towel to the bucket. It acts like an insulated pouch so I can be pretty sure that the probe is monitoring the temp of the bucket, and not the ambient air in the fridge.]
If you need to transfer it to a counter top or work bench, do so. However, I can do this straight from the fridge just by sliding the bucket closer to and just over the front edge of the fridge.
Sanitize the external portion of the spigot using a sprayer containing StarSan. Also squirt a few shots up the nozzle internally, as well. Give it a minute or two. I then use 70% isopropyl alcohol wipes on the spigot and let it dry (1-2 minutes). Some even have special squirt bottles with isopropyl alcohol to aid in squirting inside the spigot. Let it dry.
Bring a cup under the spigot (it doesn't have to be sanitized so long as you don't touch the spigot) and open the tap to fill half a cup or so of beer. Set this beer aside--it is okay if chunks of trub or yeast come along with the sample.
Close the tap.
Squirt StarSan on the outside and inside portions of the spigot to rinse away the beer and yeast. Do this twice.
Squirt or wipe with isopropyl alcohol.
Put the bottling bucket back in the fridge.
Re-attach the Ranco thermometer probe to the side of the bucket.
Take the kiddie cup off and re-insert the airlock.
Close fridge door and go figure out what your SG readings are at your own leisure (even allow the CO2 bubbles to off gas by swirling/spinning your hydrometer and let the sample come to a measurable temp [say 60F], if chilled.)
Drink your sample.
No contamination of the beer using this method.