I may be wrong, but I also have a small, garage shop and I have tried various cutting fluids. My impressions are:
I tried using a highly recommended, water based fluid, diluting it as recommended. I found that if I did not completely clean it up after a machining session and it sat for a few days, the water evaporated leaving a sticky mess. This gummed up things like a vise on the milling table and had to be cleaned up after just a few sessions. My conclusion is that water based cutting fluids are for professional shops where the machines are in much more continuous use than they are in a small shop and where they will be cleaned up much more often. For a small shop, they are more trouble than they are worth.
I use an inexpensive, light oil for cutting most metals. I brush it on to control the amount being used. Any that gets into the workings of anything, like the milling vise, does no harm and, in fact, provides lubrication. So it does not have to be cleaned up as often as a water based fluid would.
For aluminum I use WD-40. It provides a good finish on aluminum and is great for washing the chips away from the cutter. This lessens the tendency for the gummy aluminum to build up on the cutting edges.
For tapping I use Tap Magic. Regular for most metals and the aluminum variety for aluminum. Both of these are very good for cutting threads. If I am having trouble getting a nice finish while single point thread cutting, I will use them there too.
Oh, I tried some of the "kitchen" type fluids. They also had to be cleaned up after every use or they would harden in place and be very difficult to get rid of. And if they got into the workings of things like a vise, then you had to disassemble it to clean them out. I don't like any of the "kitchen" type fluids. But I will admit that I did not try all of them.
As I said, I brush the cutting OILS on to control the amount being used. I do not hose them on like you see in the internet videos. I do not try to recover them after use. But the volume that I use is low enough so that I do not find the price to be too excessive. I buy the light oil and the WD in gallon containers: I can find space for them under my bench. Others, like the Tap Magic I buy in quarts of other smaller sizes which are also easy to find storage space for.
The only real advantage that I see for water based cutting fluids is price. I can see where a shop that is constantly cutting can save a lot by using it. But, as far as I can tell, oil based fluids are not just as good, they are flat out better in terms of the machining operation.
My impressions only. I do not have real, scientific evidence. YMMV.
