I have gotten in the habit of doing reality checks throughout the day, but I also have my watch beep hourly to remind me to do one. I hoped that it would carry through into my dreams, but it doesn’t seem to have. Is there any way to make sure that you hear something like that in your dreams? I’m sure if I did hear it, I would do a reality check, since I do one every time I hear it in WL. Would autosuggestion work, or is there some other method?
The main thing is to keep doing it. It’s hard to say for sure how long it takes from person to person before it transfers, and like all forms of RCILD even once it starts happening it may not be nightly. You could try to set it to go off while your sleeping, but that may wake you up. Really, just keep at it and make sure you pay full attention every single time you do the RC so it doesn’t become something routine that your SC ignores. You could also try increasing the frequency of the alarm. There’s nothing wrong with doing excessive RC’s 
It continues through the night. I’ve had a RCILD before with my watch, which is one of the reality checks I do. (I look at my watch, glance away, and look back; in a dream the time changes a lot.) I also do a nose reality check, which is easily noticed in dreams when I am able to breathe. I think about it a little every time I do it, but I think that with three different checks that I do all at once, I’m bound to notice at least one. I do do reality checks more often than every hour; I do about three to eight an hour whenever I remember.
Your method will only work if you can clearly hear the beep in your sleep as well. You’ve made a short cut in your brain to question reality when you hear the beep, so if you don’t hear the beep in your sleep, then you won’t do the RC in your sleep either. For this reason I would suggest a different method. Learn to do a RC at specific moments that occur in both waking and sleeping life, like when: walking through a door, waking up, looking at a clock/mirror, etc.
Ok, maybe I’m just not hearing it. I also do a reality check every time I check my watch, which has gotten me into my first and only lucid dream so far (if you don’t count the one directly afterward triggered by my previous one). I just thought that I may be able to hear it in my sleep, since it’s right next to my bed.
Yesterday or the day before, I had false awakenings and they were related to the alarm so I decided to do RC every time I wake up hearing an alarm.