Probably not
this link explains the source of bitterness and how it is distributed in a cucumber:
> A natural organic compound called cucurbitacin is the culprit, according to Oregon State University vegetable breeder Jim Myers.
>
> The bitter compound is likely to be more concentrated in the stem end than in the blossom end of the cucumber. It is also more prevalent in the peel and in the light green area just beneath the peel – and less likely to be found in the deeper interior of the fruit.
and then suggest peeling and cutting the edges, using a clean knife- no rubbing is needed.
The rubbing myth probably comes from the cucumbers foaming when rubbed, which might have led to doing a false 1+1- removing the ends of the cucumber is enough, you don't need to rub it.