I thought it was referred to as Gasless welding wire? Is there a type of fluxcore that you do shield with gas?
I did find this in .035 fluxcore in the 10# spool. Is this what your searching for?
It is Hobart brand:
Hobart E71T-11 Gasless Welding Wire - 10# Spool H222106-R22
It's funny the .030 wire actually cost more. Sure its more wraps of wire on the spool, but it will still have to be 10lbs worth.
If I go with flux-core I will probably buy it from cyberweld or from my local Tractor Supply that carries this:
If I go with solid .035 wire I will go with this since I can buy local: