....has just suggested to someone with a software problem that she take her computer apart, and spray the contents with WD-40.
Whatever else you do, before it's too late, you should let this lady know that she should not be spraying WD 40 inside her computer as it is most likely to cause irreparable damage.
Your "fathead" may be worse than just stupid. He could be one of those strange people who take delight in causing problems for others.
If this lady is a Mac person you might also suggest she join FineTunedMac, where she can get appropriate, honest and reliable advice on any issues she might have....from people who know and care.