Possible.

You can get a phone number that is not registered to you. Many Ah Long got phone numbers that not registered to them.
Then you can create ewallet accounts as you like. As to how to top up, you can top up via lazada and pay via 7-11 method. I have found boost top up service at lazada.

Of course, in order for this to work, you need to kawan with Ah Long. Then they can tell you how to get those phone numbers.