@nhpaul
In my ignorance — not an expert!! — I think that if you could figure out exactly how much of your money your mutual funds have in TSLA and then buy exactly that much TSLS, then yes, it would kind-of-sort-of cancel out the good that the mutual fund is doing Tesla by holding their stock, at least in market signal terms. But it would also lose you more money than if the fund simply sold their TSLA and gave it to you as cash, because ETFs are inefficient.
In practice, this is probably more money than you’re willing to lose, and also it’s hard to figure out exactly how much TSLA they have and near impossible to adjust that on a day-to-day basis. Better to just pressure your fund to sell TSLA.