7 month old waking every 3 hours, dummy helps a bit

[n64play]

Sleep deprived advice needed :) my 7 month old boy will go to sleep totally fine (usually just after his bottle), for about 5 hours or so (lets say from 7.30 until around 2am). then he'll wake up, and cry until he gets his dummy. we put him down without a dummy but of course the bottle substituted that and got him to sleep. he'll then wake up every hour or so when he loses the dummy. we've tried leaving him, but he shares his room with his 3 year old sister, so she'll just end up being woken up if we leave him for long.
we've tried introducing a blanket or soft toy for him to cuddle as a sleeping aid instead, but it doesn't seem to be working so far.
can anyone give any more advice?

[dementedpixie]

that was the point that I took ds's dummy away as he woke for it constantly. You can either take it away or persevere until he can find it himself

[n64play]

taking the dummy away causes the issue with my daughter being woke up....between a rock and a hard place on this one!

[dementedpixie]

It will get to a point that he will settle without it which would be better in the long run though