I believe if you are claiming benefits you are only allowed to earn £99.50 per week for those 16 hours too though that may have gone up with the latest minimum wage rise.
There used to be a thing called Therapeutic earnings, now it is called Permitted Work and you have to complete form PW1
What’s the current rundown on drawing say, £62.50 JSA and doing the £99 worth of work over say, 15 hours?
An update is needed here I think. I was thinking your takehome pay for these two elements combined is £109 at most, £99 at least. In other words, even a mere 15 hours of minimum wage work nearly wipes out the entire benefit payment, taken away pound for pound once over £10 of earnings as it is. It’s intrusive because you’re constantly attempting to inform DWP of these hours and those hours performed, and they are notoriously hard to contact and speak to someone without being bald within a week from pulling your hair out. Fail to inform them of every move you make, and benefits have a habit of being stopped without warning. Even someone like me who thinks their way through the minefield can’t be arsed with such a system that’s a complete pain to negotiate for precious little return.
Better to do 30 hours of work @ even £6.20ph, gross £186 a week (around £9300 per year) and qualify for about £60 a week in non-deductable tax credit on top.
Thus, total takehome pay for that week is going to be just shy of £246 in this example, having paid pennies in tax and insurance should your full tax code be applied. 
Taking home £246 a week is similar to what you’d take home doing a full time job that grosses around £15k, but you’re only working 30 hours for the same money rather than 48-84 hours.
Gotta be better surely? Agency work can be offset for expenses, whereas full time work won’t qualify because you’re spending more than 40% of your working time commuting to the same place. You won’t get meal allowances etc. if you have a full time job either, unless some form of self-employed.
If you’ve got kids and/or a housewife to support, you’ll qualify for child tax credit as well. Then there’s all that money saved by not running a second car (stay at home wife doesn’t need one) and taxes that she won’t be paying. Ok, so you don’t get the “childcare vouchers”, but maybe like me you don’t believe in having Latchkey Children anways. 