I put the same wash level dilution in both buckets. I've got plenty of ONR and still loving it! Of course one has to remember that ONR is a safe way to wash and clean almost anything so it cannot have the "bite" to clean everything. If the situation demand, you have to use other cleaners (like power clean etc.).
I steal this thread a little bit, do Optimum have a relatively safe tar-remover like Auto Finesse Citrus Power, which I find is the best product against the "salt" (read tar from the road surface lifted by the wintertires) in the winter? There are many tar-removers that work, but few of them are safe in any way if you try to keep the maintaine the LSP as long as you can. Of course with Opti-Seal (it so simple!) you don't have to care about LSP longevity in the winter, but it is nice to learn about different processes.