1.Pay to query the Alexa data base with your own script ...

So, you would need a list of the top 1 million Alexa ranked websites -- no idea if that is available ( me thinks you can buy it from AWS (Amazon Web Services) AWIS (Alexa Web Information Services)
[Oh Yeah!

Pricing: $0.0025 per URL returned (e.g. $.25 for 100 URLs)
(Alexa Top Sites is sold by Amazon Web Services, Inc.)]

2. Buy It NOW! $2,500.00 :P all compiled

You would need to extract the ones that you want.
if AdultContent:no,
or
if AdultContent:yes,
elseif AdultContent:,

So, it's a $3,000 to $4,000 job.

Here is a sample I made,and paid for just as a demo as I needed this for other uses anyway.

Caveat: People submit false information on their content to Alexa. I guess Alexa dos not verify this. Still, the false data less than 1%.