A pretty bold idea but it could work have that much money to invest with and you have a strong emotional capability to handle rumors or news about the coin you invested with. What if let's say for example that the price of a specific coin decrease by 500$, then you invested again your money, and after a few hours or days, it started falling again? You can't keep investing in something unsure unless you are really confident about it and also if you are in a tight budget, you can't prioritize investing to this without gaining som returns first.
Also, this technique requires you to be very active in monitoring the price movement of the coin you invested on. So, unless you can meet these requirements, you should think twice before doing the same thing.
Nonetheless, it is a great strategy and this could work on Bitcoin and Ethereum where you can be sure that its price will recover despite the dips that it is having.