It is very difficult to index links these days. Did anybody try omega indexer?
The problem is, that the name is basicly bullshit. No service can actually index in serps. They can index in crawling index - if there is a bot, google has indexed the page in it's crawling index. It will still have to run the typical tests and categorization, every page has to run through. Indexing Services can help bringing bots - or even force bots. You can bypass crawling budgets with it for example. Wich is a great help. But that's it - a page gets pushed from crawl-index to serp-index by googles quality measures, not by services and there is no service, that can change it (Well, backlinks and authority do, but that's not classical indexing

). Indexing Services can handle 3rd party urls, though - when it comes to own pages, I would still recommend the search console. If you can't index it via these tools (and are not limited by crawling budget), no indexing service will change this as well, since it's not possible on a technical level from outside*. But on 3rd party pages, you don't have controll about the crawling, forcing a crawl can be productive.
I used omega a while ago, had some good values with em, but they broke down to not bringing any bots. I think they used the translator-method, that worked a while ago, but google closed this gap. I can't say, if they changed to another method (I heard, they kinda relaunched though, just didn't test yet. They might have gotten it, since there are methods and have been a useful service 2 years ago, so might worth a try.
* There was one exception, google news. This was because algos have a problem with stuff they don't know. They can only rank by parameters of the past, stuff they have seen - and they obviously haven't seen news. So you need to bypass the algo, if you want to index news in time to your search engine. Wich is pretty significant for google news =D
I think, it still works for a news site itself, but not for newssited backed links (wich news-indexing-services mostly did) since the newest updates. But thats just hearsay, I didn't actually try it on my own
