Most paycheck parking examples assume a tidy salary landing every other Friday. Plenty of the people most interested in this strategy don't live like that. Commission months that swing by thousands, seasonal businesses, invoice-based income that arrives whenever clients feel like it. Does parking still work? It does, and in some ways it fits lumpy income better than a savings account does, but the setup has to respect the lumps.
Start with your floor, not your average. Averages lie to irregular earners. Add up your last twelve months, sure, but then find your two or three leanest months, because that's the income your baseline budget has to survive on. A budget built on the average will spend money in March that doesn't arrive until August. We covered finding the real number in Find Your Real Monthly Surplus, and for irregular income the honest version uses the floor.
Then let the line do what it's built for: absorb the timing. In fat months, everything above the baseline goes against the line and drops your average daily balance hard. In lean months, you draw living expenses back out. The line becomes the shock absorber between when money arrives and when life bills you, which is precisely the job a line of credit does better than any other tool. A savings account can do this too, I'll grant that fully, it just does it while your buffer earns a little and your debt costs more, instead of your deposits canceling interest directly.
The danger is that the line makes lean months painless, and painless lean months invite spending creep. If your baseline grows to match your good months, the line stops absorbing timing and starts absorbing lifestyle, and the balance ratchets up instead of cycling down. That failure mode gets a full writeup in The Math Works Until Spending Creep Breaks It. Irregular earners should also hold a bigger untouched margin on the line than salaried folks, for the season that runs long.
Getting the line approved is its own project when you're self-employed, since lenders typically want two years of tax returns and they underwrite off the income your accountant worked hard to minimize. Apply during a strong stretch, not during the drought when you need it. The line you set up in good times is the one that carries you through the other kind.