I've tried to use a cucumber on myself and it was just too wide. It hurt.
Shelly,
You are wise to stop if it hurt because of width. Guideline #1, if it hurts in a damaging/wrong fashion stop...period.
That being said, when I was 19 and into my early 20's, I began to experiment with cucumbers. I found that cleaning out with enemas until there was nothing else to come out a real benefit, then I focused on the narrower long ones no bigger around than my rectum would normally open, favoring a small rounded tapered end that would definitely be easy to insert and gently dilate my rectum, a little lubrication will be helpful too. Then I lay down in a comfortable position that allowed me to relax my rectum and proceed at a rate that was comfortable for me, not rushing and taking all the time that is needed. There is no rush,relaxation is very important.
Remember there is no need to rush, if it requires several attempts over a period of time, then that is ok, your body needs time to adjust and the brain needs to learn the sensations thereby allowing you to relax your rectum and making it more easy and ultimately pleasurable. A very effective way to begin is with very small and gentle insertions & withdrawals over several separate sessions, as you become accustomed to a certain depth and diameter, you can move on to a little more in subsequent sessions gradually working yourself up to what is right for you. How long it takes is different for just about everyone because each persons individual anatomy and rectal elasticity is different, it will happen painlessly if you are willing to take your time. Solo at first is helpful because you are in total control of the process without distraction. After you have become completely/totally comfortable with inserting the size cucumber that is right for you, then consideration of letting someone else do it for you is a more reasonable option. I hope you find something useful in my humble recollections of how I started. To this day @58, I still use a handy cucumber when the mood strikes me, most of the time it is when I am somewhere and don't have access to my butt plugs & dilators. Even sometimes when at home and have all my toys ready at hand, I will buy a cuke and use it instead, just because it feels good. 😄
Sincerely,
G.N.