Grammaticalization Paths: Comparative Construction from Dough

I've been thinking a bit about neat grammaticalization paths, spurred on by hearing of a language where the development of the meaning of a particular word went something like

wood > stick > tool > [forgotten steps] > something like a perfect aspect marker

happened. Similar things probably have happened in loads of languages.

I propose the following path:

dough (noun) > swell (verb) > overflow, exceed, for instance wrt the size of a container

One of the common ways of comparisons to be formed is the exceed comparative, for which wals.info gives the following example:

Duala (Ittman 1939: 187)

nin ndabo e kolo buka nine

this house it big exceed that

'this house is bigger than that' 

So, seems rather possible that a noun for dough (or even more generally, some suspension of gunk in liquid, which then turns into 'dough') could become a verb for comparative constructions.

bibliography:

Leon Stassen. 2013. Comparative Constructions.
In: Dryer, Matthew S. & Haspelmath, Martin (eds.)
The World Atlas of Language Structures Online.
Leipzig: Max Planck Institute for Evolutionary Anthropology.
(Available online at http://wals.info/chapter/121, Accessed on 2015-06-27.)

Ittmann, Johannes. 1939. Grammatik des Duala. Berlin: Reimer. (Not a direct source, but quoted as quoted by Leon Stassen - in this context it is not to be taken as an absolutely certain statement about the Duala language, but as an example of the kind of structure discussed. I find it highly likely it is an accurate description of Duala, but the relevance it has in this post is just as an illustration - even if it were a completely misanalyzed sentence, it would fulfill its function in this context. tl;dr - take it as an example, if you really want to know things about Duala, go to a more direct source than my post.)