For one, this thread is about bitcoin and not shitcoins, and secondly, DCA does not work with shitcoins because they are not long term investments that have any fundamental and/or long term value.
DCA tends to apply quite well for bitcoin and/or long term investments bacuase it allows you to build your position over many years 4-10 years or longer.
Shit coins are equivalent to gambling and gambling is for losers. One can invest few bucks in shitcoins for fun but real focus and most of your capital should be going to Bitcoin alone.
One thing to note about DCA is that it's not for people with low patience as it takes years to build a profitable portfolio with DCA. So anyone coming to DCA should keep in mind that it will takes years not months.
Of course, if you are still in your accumulation stage, you can supplement your accumulation with buying on dips and also lump sum investing, and so only you can figure out which accumulation methods to apply and when you might consider yourself to no longer be in accumulation stage... and yeah, a lot of newbies might have chances to build their investment into bitcoin over 4-10 years or longer, and they likely end up selling too much too soon and then likely putting themselves into a worse place than if they had just focused on accumulating through the varying buying techniques rather than selling, trading and/or gambling with their investment.. in such a great and powerful (and option providing) asset, such as bitcoin.
We can relate with this with current bull run where people are selling too early. It's not a success that you buy at 60k and sell on 70k since this will give you only a limited profit. One must have a plan where he must gather bitcoins before he start thinking to sell some of his holdings. How many Bitcoins are sufficent is a subjective question. So some people 100 Bitcoins are low while for many getting even 1 bitcoin is difficult.