This works, but only if you're sampling the exact same space as the block size. For example, if your cipher outputs 64-bit blocks, but you want to sample in 2^32, you're back to the drawing board, because there's no way to truncate the cipher output without risking duplicates.
You can use the "hasty pudding trick" to truncate the cipher output without risking duplicates. It is inefficient if the block space of the cipher is much larger than the sampling space, though.
However, you can also use a Feistel network to create a block cipher for an arbitrary bit length. So, you can always bound the block space to be no more than twice the sampling space, which is okay.
A variable-size block construction would help here. It doesn't even have to be cryptographically secure, only bijective and statistically good enough similar to PRNGs sans CS. It doesn't even have to be keyed.
