I used 12 Giants, 8 WBs, 40 Barbarians, 4 Hogs (for luring the CC) and the rest are Archers to farm DE when I was a TH9. I farmed 6k-9k DE per hour, depending on how good or bad the loots are in C1.
IGN: Leryx Emberlaze | Status: Slightly Inactive (Attacks won/season = 20 to 60) Current stats as of April 6, 2015 (GMT+8): Started playing on Mar. 30, 2014, semi-quit on Sept. 18, 2014, and came back to the game on Nov. 2, 2014. Stopped actively farming starting April 6, 2015.-
lvl 133 | TH10 | 1.15 billion GG | 3.18m HH | 62 lavas, 188 legos | AQ 27, BK 20
loonion or barch up in masters. Iv maxed both my heros at th9 so have actually done it.
you can barch lower down if you want but if you use loonion then head up to master 3 for that nice 100k/100k/500 bonus.
The key i have found is to not be stingy with spells. alway's boost the spell factory and drop 3 or so spells per attack. so you just blitz the deffenses and take all the DE.
I was getting 50k per day towards the end when i was farming them.