Hi cydonia. You quote the advice to the letter - until bf is established.
The main reasons they shouldn't be introduced early on is because that suckling (yep he's using you as a soother) establishes your supply by telling your brain that more milk is needed because at the beginning, your body doesn't know how much milk to make.
So, if DS is putting on weight, having dirty nappies, perhaps even posseting too, then the extra sucking could be for comfort (boobs were here way before dummy'!) as your body is making the required quantity of milk.
It genuinely is up to you. The dummy police aren't going to shoot you 
You could limit it to evenings only, or all the time, it's your call.
Obviously eventually they get used to it and perhaps reliant on it to go to sleep but then some babies get reliant on falling asleep on boob too, so you have the benefit of moving away from them if they'll accept a dummy.
I too'd and fro'd for a while but at 2 weeks, cracked nipples due to tongue, then mastitis, i just needed a break of 'sucking' I gave in a offered dd one. She refused it typical. DP and I would take it in turns to hold a little finger in her mouth whilst in the Moses baske and she'd suck on thatt. Some babies are 'sucky' babies- mine use to overfeed by sucking because i had a good supply and letdown, she'd then throw up (over herself and basket) because she'd had 'too' much!
She eventually took a cherry shaped one (the old fashioned style ones) which reduced the sickness and let my nipples heal the few poor latches at the beginning. At 11 months on, she doesn't have it during the day out and about, only for nap or sleep time. Just my personal 'rules'.
Hope you get some rest. 