So I have instead said "Moжно пожалуйста..... х.....?"
But I am beginning to suspect that this sounds a bit stupid, or at least that it is an un-Russian way of speaking??
No, it's a good way of speaking Russian. Although a sales person does not usually think of how you addressed her. Remember only that "ты" is unacceptable.
As far as I know, one should raise intonation on a verb to make a polite request in Russian.