JFFS2 partition in a USB (just Asuswrt, no Merlin)

Hi,

I've two networks, one with a N66u and Merlin and the other one with a DLS-N14u.

I would like have the JFFS2 writable partition in order to "install" thins and keep scripts in the DSL-N14u.

Coudl I use a USB memory and create a partition to prepare this writable and consistent content?

Thanks in advance.