Dear Kunjuppu Sir,
Why? To save time and fuel!
One L P G refill lasts for 70 + days for me and Sing. Chennai mAmis are wonder struck to hear this! 
raji does this pressure cooking remove the gooey kozha kozha texture of the vendakka? if not, do you think, if you put some tamarind in the water, that would do the trick.
we cook vendakka two ways: one is straight forward low heat, long time, 500 grams 1 hour, with salt asafoetida chillipowder turmeric and oil splattered with mustard seed.
the other is first saute the vendakka for 5 minutes, or just browning (on the skin the gooey goes away). set aside, for 1/2 kg, 250 tomato, 250g onion sauteed with salt garam masala asafoetida turmeric and 6 Tablespoon oil. when well done, add the vendakka.
much as i luvvvv this veggie, and so do my kids, all effort appears to remove the gooey.btw here is a funny story: in the 1960s, my young cousin, married and rented a flat behind our home. she made vendakka something, and it came out as one long string (seen to be believed). mom suggested she boil it again with some puLi added
