What you need to do is just put the orange peels in a bottle and soak them in vinegar for about a week. Most bloggers who live in cooler climates would recommend soaking them for 2 weeks. But, for hot and humid Malaysia, I find that a week is just fine. If you decide to soak them for longer though, that's fine too :)
I think the concentrate smells very pleasant. It's got this strong, orangey aroma. If your concentrate doesn't have this amber colour, don't worry. This batch was actually soaking for more than a week, as I had been busy. I find that if I leave the concentrate at room temperature, it will start to turn dark brown after a while. I don't think that affects the potency of the concentrate though. But still, you can store it in the fridge if you like.
To use your concentrate and make a cleaner, just mix the concentrate with some water. You can use 1 part water to 1 part concentrate, or dilute it even more. You can also use it full strength for tougher stains. I don't have a squeeze bottle, so I'm using an empty liquid hand wash bottle that I had around, to store my diluted cleaner. I use the cleaner mainly to clean my kitchen counters and the stove area. It really works! Cuts through stain and grease like a charm. Of course, you can use it as an all-purpose cleaner around the home.
After you've drained your concentrate. Don't forget the peels that have been soaking! Squeeze them out and you'll get even more concentrate (see pic below). You can also put the peels to good use before you throw them out (or better still, compost them). I use them to scrub my kitchen sink! Just rub them all over your sink and leave it for a few minutes, then rinse. Your sink will be clean and smell fresh - all without harsh chemicals! My son came into the kitchen as I was cleaning the sink with used orange peels this morning, and said, "It smells really nice in here!"
By the way, this is how much concentrate you can get from squeezing the soaked peels. You can keep leftover peels in the fridge, because they work great as a deodoriser! I also like to chuck a few into my sink, to make it smell nice :) And yes, you can also make this cleaner using lemon peels. In fact, here's 31 things you can do with your lemon peels!
PS: In case you're wondering, I use regular, locally-made vinegar, which costs around RM2.00 per bottle. Also, although this cleaner is non-toxic, it can be quite abrasive. If you have sensitive skin, like me, do put on rubber gloves as you're cleaning :)