I am also breastfeeding mom, my baby also needs to suck into my breast for sleep everynight, i let him do this as it is very common for breastfeeding baby, you should be pround since you are the only one give him this comfort. i think it is meaningless to give him the dummy, it is no taste and will affect the growth of teeth later, your baby may not want this.
also, baby is very clever, when you are out, he knows he does not have nipple or breast milk, he will not cry for this. try to ask your husband to hug him to sleep .