Stop-loss is to stop your loss. DCA is to average your entry price over time. Their names are different and also represent the core ideas behind. They can not be use as alternative because stop loss is for exit, DCA is for entry. You can not call an exit is also an entry. That is very weird and never be true.

However, you can do your stop loss at $40k and make a DCA at $30k. Stop loss first and wait for price falls deeper to make DCA. So if you want to apply this, you have to do stop-loss early enough so that you can wait for deeper falls which would be -20% from your stop-loss price. At which you will have a new entry, for DCA.