I usually obtain gold in trades or from goody huts, and I use that for the embassies.
Also, at the end of a research project, I lower the SCI slider to prevent overrun waste.
(say, a project costs 100 beakers to complete, and you generate 24 beakers per turn, then you can run 100% SCI for 4 turns, and the 5th turn you only need 4 more beakers, wasting 20, so that last turn you can safely set the SCI slider to 20% and still get the tech in 1 more turn plus 20 gold)
If you decide you need to spy on the capital, (for example, you ant to know if you can complete a wonder) and you are low on gold, then by all means, lower the SCI slider to 0% for a turn or two.
What I wouldn't do though, is collecting gold for no clear purpose, at the cost of research time.