For the formal model please check out my earlier post regarding different legal implications of DAICO model:
Also currently TheAbyss is running DAICO: https://www.theabyss.com/
They removed Oracles from the refund voting process. The refund starts automatically once per quarter, up to 1.5 years if I recall correctly. This was because in real life it was hard to find people who volunteer to be Oracles. Furthermore TheAbyss has some hard coded addresses that cannot vote (reserve pools).
Furthermore I recmmend that the first step of tap is asymmetric and notably higher than subsequent steps. This is because you need to make all sort of payments after the token sale is over. Most notable the gatekeeper payments like 1-3M USD for Binance and such for listing the token on exchanges.