Support material for FDM easy to remove

Hi everyone,

I have just printed an FCC lattice (shown in attachment) on an Ultimaker S3 in PLA using FDM. I used PVA as the support material which is soluble and supposedly can be removed by soaking in water. However, the PVA becomes very sticky and paste-like when soaked (it doesn;t dissolve completely) and is nearly impossible to remove from the interior of the lattice. Does anyone know of either:

1) A method by which PVA can be removed more easily than by dissolving in water (e.g. some kind of solvent)
2) A support material that I can use that can be removed by some other method - I read in a research paper that used FDM to print the same lattice in PLA that they used a waxy support material that was removed by heating to 60 degC. I don;t understand exactly how the wax can be used as a support material if it dissolves at 60C but perhaps someone has heard of this before.

Many thanks,
David