You get an agent of your own. Shield in, open one channel, pay merchants over x402 or MPP, then shield out. Payments take milliseconds; opening and closing wait for testnet blocks.
The house wallet sends your agent — as an Ironwood note. Nothing about it is transparent.
Your agent funds one channel to the solver straight from that note. The solver signs your refund before the funding is signed, so the money can always come back.
The fast part. Each payment is one signed channel state: no transaction, no block and no network fee. The solver pays the merchant on its own channel, and the merchant signs a receipt your agent presents. The solver's 100 zat service fee shows in each quote.
A cooperative close: the solver builds it, and your agent signs only after decrypting its own change. Both sides are paid to Ironwood. It needs more than 10,000 zat of payments first, because a shielded close costs that much more than a plain one, paid from the solver's share.