It depends on both luck and your ability honestly.
I do legit things on my account and I am usually online about 12+ hours (I play at work and such).
This most likely means no flags for me for playing a lot. I would recommend that you dont bot for more than 6 hours / day either way, I rarely go over that, just in case.
If you are strictly looking for money, barrows is not the best option. Zulrah would be best, however the ban rate there is much much higher than at barrows. Bot smart, live long.
As I said in my previous post, DO NOT use Mirror mode if you cannt babysit the whole time its running. Its not the fault of the scripter, the Mirror client is just garbage, doesnt provide good enough support for a script like this (many many issues, I usually have to step in about 4-5 times each hour to fix the client manually, not to mention it doesnt even work on low end pcs, with this script at least). The injection client you can leave there for however long you like, runs perfectly.
As for reference, the GP / Hour at barrows with OK gear is about: 300k / Hour without uniques.
If you get uniques it can go as far as few million but that would mean you got multiple barrows items and that they also were on the expensive side (most items are 200k or less).
Good luck.