My sister-in-law gave me the idea to make our own teething biscuits for the babies. They love Mum Mums, but the Mum Mums dissolve so quickly that our babies need something more substantial to play with chew on. Here are the steps I used to make our own teething toasts:
Buy some french or country bread.
Cut it into your desired size. I cut mine about 0.5 to 0.75 inches thick and then cut each slice in half width-wise.
Put on an ungreased baking sheet.
Bake at 250 for 60 minutes.
Voila! You now have cheap, healthy teething biscuits. I store them in an airtight container, and even take them in a smaller plastic container when we're eating out. So far, Miles and Vivienne seem to really like them. They do get a bit crumbly, though, so I would recommend using a bib and keeping an eye on your little one so they don't choke or gag. =)