I was doing similar stress test shortly after fork https://steemd.com/b/41845285#645381beee9632ef28948e1e6955f900c7bb4a9b
Was posting 40kB of random data every block into blockchain (this is a limit one account can throw every 3 sec). Zeroed my RC worth 10k SP in 1-2 hours.
The more we stresstest - the less is our power becaues RC system is self-adjusting. In the long term I could spam less and less.