I have a new website (it is in Russian) but targets Belarus clientele at ÑÐ²Ð°Ð´ÐµÐ±Ð½Ð°Ñ Ð²Ð¸Ð´ÐµÐ¾Ñъемка so I was able to get into top 10 Google for the targeted keywords like видеоÑъемка Ñвадеб МинÑк, ÑÐ²Ð°Ð´ÐµÐ±Ð½Ð°Ñ Ñъемка в МинÑке in just 2 - 3 weeks. But before I started I ticked set regional search only - Country: Belarus in Google webmaster tools. Do you think that it sounds like a way to overcome Google sandbox filter?
Google love new content, that is, new sites and new pages. Google give them a New Content Boost. This Boost help new sites rank higher, even on the top of search results. But this high ranking in search results is only temporary. After some time, new sites or pages go down ion search results or completely vanish.
I don't think it's a way to escape, but good for you that's your site is still ranking. anyhow the sandbox only target commercial and competitive keywords.