You don't have to take constant readings. If you are doing what many of us are and leaving your beer in primary for a month, then bottling, then you really only need two readings, and that is really if you want to know if you hit your target gravity, and what your alcohol by volume is, and you do that one at bottling time.
If you choose to secondary, which less and less folks are doing, again if you give it sufficient time, and I recommend 14 days after yeast pitch, you could take on to see how close to your target gravity is. Or you could just rack it over.
The only time you really need to take a bunch of readings, is if you are worried about whether or not fermentation is happening. You don't go by airlock readings, anyway...but if you don't trust the yeast then that's when we recommend taking readings....Because that is your ONLY REAL diagnostic tool.
But if you come to realize that unless you pitched your yeast into boiling hot wort, that fermentation is going to happen, and that yeast RARELY doesn't work.
In other words if you trust the process. Then you don't really need to take a lot.
Now if you decide that you you just have to secondary
and THINK you NEED to do it immediately, then that's when you need to think about multiple readings....that's where the 2 readings over 3 consecutive days idea comes into play.
Now having said that, If using basic sanitization, taking a hydrometer reading is no risk at all. Like others have said there is a layer of co2 that protects your beer, and even taking multiple readings is nothing to worry about.
This is what I use, and it works with both buckets and carboys
Here's what I do....
1) With a spray bottle filled with starsan I spray the lid of my bucket, or the mouth of the carboy, including the bung. Then I spray my turkey baster inside and out with sanitize (or dunking it in a container of sanitizer).
2) Open fermenter.
3) Draw Sample
4) fill sample jar (usualy 2-3 turky baster draws
5)Spray bung or lid with sanitizer again
6) Close lid or bung
6) take reading
It is less than 30 seconds from the time the lid is removed until it is closed again.
Probably less if you have help.
And unless a bird swoops down and poops in your fermenter, you wont have any trouble.