Vasalene market research

An salesman of Vasalene cream was doing a bit of market research
on his product, going house to house and asking people what they
thought of the product. Towards the end of the day he knocked
on the door of his last house and a woman in her early thirties
answered.
The salesman introduced himself and asked if he could ask the
woman a few question about his product, which she agreed to.
The first thig he asked her was "how effective do you find our
product"
"Very" she answered "It alway does the job required of it"
"Do you ming if I ask what it is you normally use the cream for"
enquired the salesman.
"Certainly, I use it for sex" answered the woman.
Well the salesman was a little taken back by this "That's a very
candid answer miss, I mean, we know our product is used like
this, but no one ever admits to it. Would it be too personal to
ask how it is used?"
"Not at all" said the woman "when me and my husband are feeling
frisky in the bedroom, we put some of your cream on the door
handle, to keep the kids out!"