Imo it is not possible for google to detect properly spun content, it is not worth computing power it requires. They can do this using ngrams for example, but it is uses a lot of queries. And for example article spinner I coded beats this algo, so google cant detect that the content is spun. Manual spinning is also good but it takes more than 30 minutes per article.
There is also the option to spin capitalized words (assumed to be proper nouns) as well as leave any number of words unchanged, depending on whatever you enter into the "ignore" field, separated by commas. You also have the option to only keep the sentences that were altered a minimum percentage, as indicated by the "Keep Sentences that Changed" option.
The method is very simple, if you have the know-how of computers and internet then using this tool should be no trouble for you. All you have to do is copy and paste your text or article in the text box, and then click on the button saying “Re-write Article”. If you would like to play a little with this article rewriter tool before you go for it then you can use one of the given samples and watch it do its thing.