The Monster of Doubt

It all happened on Christmas Eve. Last moment preparations, with shops closing early. My wife went shopping, I and I stayed with my family (or her family - my wife's sister with her husband, and their children). My job was to do some cleaning and also to borrow a small type of mixer/food processor for drinks or I am not sure exactly for what. So I went to the neighbour to ask her for it; she was very happy to let us have it over Christmas, however she wasrather worried about the condition it might have been in, as she had not used it for a while. She took it out of the box, and it was covered with something that look like mould (but started disappearing in daylight). She called the stuff "burn", and she assured us that it would get cleaned easily.

My brother in law looked at it in horror. We said we would think of it. On the way back to our home, my brother in law suggested that I buy one myself before the shops close.

And here it all started. 

Shall I give in to his advice and buy it?
Or shall I resist and remain strong and in control?
But if I stay in control, I will not have the mixer (or a clean and hygienic mixer)?
And if I go and buy it, I will do what he said and not what I decided to do.

Or maybe I shall thank him for the advice and say that I accept it?