I too doubt it will help. DS was breastfeeding up to 5 times a night at 11 months of age. I never thought I would sleep again!
We ended up putting him in his own room just before 12 months and substitued a few of the overnight feeds with water and within weeks he was sleeping 12-14 hours with no feeds. I have absolutely no idea why he decided then and there to stop the overnight feeds.

Solids and formula helped neither of my kids to sleep longer. DD is formula fed and a hoover when it comes to all things food and she still wakes at night for feeds.