Having "blessed" the use of methylene chloride, I feel I should comment further - - -
Methylene chloride, while very useful and in widespread use, is not benign stuff. Harmful exposure can occur through breathing and skin contact. Read the Wikipedia entry.
https://en.wikipedia.org/wiki/Dichloromethane
If you use it (as I have and will continue to use till I run out), at a minimum, be sure to provide very good ventilation and keep it off your skin. Using a good respirator with an organic vapor canister is not overkill. Leaning into a canoe to scrape out this stuff after it has been soaking into loosening up old varnish for a half hour is a good way to get a substantial hit.
Information about the harmful nature of useful chemicals is much more available that it was when I was young. I paid for a good part of my college education doing production machining of aluminum castings -- we used trichloroethylene, and I regularly breathed its fumes and splashed it on my hands. I worked on my cars and motorcycle, and washed my hands with gasoline and thought gasoline smelled good (it did smell different, and better, than it does today). Our house was insulated with foam in the early 1960's -- formaldehyde? Over the years, I have occasionally stripped furniture (not opening the windows if it was winter), used various pesticides including 2, 4-D (a component of agent orange). and various other consumer chemicals. I worked a block and a half from the World Trade Center and and was exposed for months to the dust and fumes resulting from its destruction. I've worked with plywood and various wood-composite materials -- more formaldehyde? And I always have a variety of solvents in my shops and garage.
The motto of the time -- "Better Living through Chemistry" -- was intended to, and did, lessen and detune any sense of problems or dangers from chemical use and a chemical-laden environment. Warnings, if any, were in fine print and often not taken very seriously. Little attention was paid to the carcinogenic effects (known or suspected) or the neurologic impairments or other toxic properties (nausea, dizziness, fatigue, headaches) of all sorts of materials.
I am 74 years old. In the last few years I have had two cancerous growths removed from my skin; I have developed a bit of a balance problem (those who took my poling class at Assembly two years ago my recall that I fell out of my canoe a few times -- a sign that I could not ignore); I have lost some of my sense of smell; and I have a slightly diminished field of vision.
Now all of this may be simply age-related -- growing old is a bitch (though better than the alternative) -- but it is entirely likely that my fairly casual exposure to powerful chemicals over the years has contributed in some measure to these conditions.
Much more is known, and information is more readily available, about the negative aspects of our modern environment. The life expectancy of a male in the U.S. when I was born was 63.6 years, and I have gone well past that benchmark, in no small part due to the chemicals that I use and that surround me as I go about my daily activities.
BUT -- it would be foolish in the extreme not to pay attention to, and not take steps to minimize, the harmful effects that come with the benefits of modern chemicals. Today we all have information readily available to us -- look up the MSDS for the stuff you use and pay attention to the warning labels on stuff you use. Even though they sometimes seem excessive, they are not there for decoration or because a manufacturer likes to put negative information about a product on the container.